Except as otherwise provided in criminal proceedings by section 3500 of title 18, United States Code, if a witness uses a writing to refresh memory for the purpose of testifying, either--

(1) while testifying, or

(2) before testifying, if the court in its discretion determines it is necessary in the interests of justice,

an adverse party is entitled to have the writing produced at the hearing, to inspect it, to cross-examine the witness thereon, and to introduce in evidence those portions which relate to the testimony of the witness.

In Thomas, the plaintiff brought a civil action for damages and remedies against Euro RSCG Life after the company allegedly began discriminating against her after she returned from maternity leave.

At plaintiff's deposition on January 20, 2010, plaintiff testified that she had looked at notes in preparation for her deposition that recounted the dates and substance of conversations plaintiff had had with former in-house counsel for defendant Euro RSCG Life, Peter Glass....Defense counsel promptly demanded that the notes be produced, but plaintiff's counsel objected on the ground that the notes were protected by attorney-client privilege.

The defendant thereafter moved to compel production of the notes, and the court found that while the notes would otherwise be protected by attorney-client privilege, the plaintiff waived the privilege by relying on the notes in connection with her deposition testimony. Of course, under Rule 612(2), the court also had to find that production was necessary in the interests of justice to grant the defendant's motion because the plaintiff only relied on the notes before testifying. And, according to the court,

just such a finding is compelled here. The notes are simply a factual recitation, arranged chronologically, and evince no work-product concerns. They relate to conversations about which the witness knew she would be questioned: indeed, plaintiff's counsel, in an earlier in-court conference, had repeatedly referenced these conversations as a basis for seeking various discovery in this case....Finally, since the subject matter of these conversations, and the conversations themselves, are likely to play a substantial role in plaintiff's case, it is in the interests of justice for defendants to be able to adequately cross-examine plaintiff by having access to notes that plaintiff admitted to reviewing so that she could answer questions "accurately."